Semiconductor fabrication processes include fabrication of interconnects to form circuits. Interconnects may be formed with copper, capped by liners such as tantalum and/or tantalum nitride, or may be formed with tungsten. However, a copper interconnect may result in electromigration, which can lead to void formation and device failure and tungsten interconnects may have a higher resistivity. As a result, interconnects formed using other metals are of interest.